Gate's Design
by Batsutousai
Summary: One morning, Ed and Roy wake up in the wrong bodies. Which would be a lot easier to sort out if they weren't in different worlds.


**Title:** _Gate's Design_  
 **Fandom:** _Fullmetal Alchemist_ '03 anime  & _Conqueror of Shamballa_  
 **Author:** Batsutousai  
 **Rating:** Teen  
 **Pairings:** Edward Elric/Roy Mustang  
 **Warnings:** Ed's potty mouth, pre-slash, canon typical violence, hints of angst  
 **Summary:** One morning, Ed and Roy wake up in the wrong bodies. Which would be a lot easier to sort out if they weren't in different worlds.

 **Disclaim Her:** This story is based on characters and situations created and owned by Arakawa Hiromu and various publishers. No money is being made and no copyright or trademark infringement is intended.

 **A/N:** For RoyEd Week on tumblr. Today's prompts included _Body swap_ and _Reunion_ , and I've been halfway looking for a reason to do a post-CoS fix-it, so.

Given time constraints, this hasn't even had a brief reread, so apologies in advance for any glaring errors. I'll get around to an edit reread in a month or so. XD

You can also read this at Archive of Our Own, tumblr, or LiveJournal.

-0-  
-0-

The first thing Ed noticed upon waking, was that his ports didn't ache. Which was rare, but not improbable, especially since he'd got the replacement automail from Winry during his brief trip back to his world.

The second thing he noticed, upon opening his eyes, was that one of them...wouldn't open. He reached up with his left hand to figure out what was wrong, but froze partway, right eye fixed on the unfamiliar table and the bottle sitting on it, which had the words _'AMESTRIS'S FINEST'_ written at the top of the label.

"What the fuck?" he breathed, except it wasn't _his_ voice that came out, but a stranger's.

He shoved himself into a sitting position on the dull grey couch he was laying on, stopping for a moment on the very much _flesh_ hand resting on the back.

He shook his surprise away and stood, brushing hair away from what felt like a scar where his left eye should have been.

 _What the fuck was going on?!_

It took him a bit of stumbling and banging his too-long legs into unfamiliar furniture to find a bathroom. In there, he flipped on the switch for the light, blinked past the familiar brightness of an Amestrisan bulb, and turned to the sink.

Where a mirror should have been, there was only the wall, with holes where the fastenings that would have held it in the wall should have been. Like whoever's body Ed was in couldn't bear to look at their own reflection.

A shrill ringing started from somewhere else in the flat, and Ed stumbled him way into a bedroom that looked like its owner hadn't bothered to _pretend_ they would be using it, the mattress stripped bare, with a pile of pillows and blankets tossed near the head.

The ringing was an alarm clock, and Ed found his way clear of any of the strewn clothing he was known for as he crossed the floor. Next to the clock, he saw as he tapped it off, was a pocket watch with a familiar crest emblazoned across the front, and he picked it up in the silence and clicked it open.

It opened smoothly, nothing written on the inside. And Ed hated that he felt let down as he let the watch drop to his side; had he really been expecting to find _his_ watch in a stranger's house?

He sighed and turned, only to freeze again, this time at the sight of two photos sat on a dresser. One was of him as a kid, scowling in that way he always had when someone – Hughes, it was always Hughes – cornered him with a camera. The other was of Mustang and Hughes, looking so young, grinning and with their arms around each other.

Ed swallowed and picked the photo of Mustang and Hughes up, his chest aching with loss, far more poignant than seeing the Hughes of the other world, or seeing little hints that he was back in Amestris. Somehow. Impossibly.

His gaze caught on his reflection in the glass of the photo frame, and he almost dropped it when he recognised it: Mustang!

He was–!

 _How_?! _Why_?! Where was Al? For that matter, where was _Mustang_?!

Most importantly:

Now what?

-0-

Everything _ached_.

Well, maybe not _everything_ , but it felt bone-deep. Like the last week in Ishbal, when all Roy had wanted was to snap and burn _himself_ to ash. Or after his fight with Bradley, and Archer shooting him, while he'd been struggling to come to grips with the losses they'd suffered. Except...

Except those aches had never been centred on his right shoulder and left thigh.

Roy opened his eyes to an unfamiliar white ceiling, the brushstrokes done in swirls, which was just _odd_.

Had he been kidnapped?

A door opened and a familiar voice said, "Oh, good, you're finally up. We need to get moving if we're going to catch the train."

Roy turned to watch as Alphonse, wearing the same dull brown shades Edward had worn during his brief return visit, was tiredly opening a dull brown suitcase. "Alphonse?" he asked, but his voice wasn't _his_ voice. Was only vaguely familiar, like he'd maybe heard it at a different pitch?

"Brother?" Alphonse returned, looking back and shooting Roy a tired sort of amused look, which quickly morphed into one of concern. "What's wrong?" he asked, sounding...older, almost. Not at all like that hopeful, too-young boy that Roy had tossed back up to the skyship before Edward had returned it back to that other world.

Roy shoved himself into a sitting position, wincing at the flare of strain from his shoulder. _No,_ he realised, looking over at a familiar automail arm from an unfamiliar angle, _not_ _ **my**_ _shoulder, but_ _ **Fullmetal's**_ _._

He lifted the foreign hand and fisted it, intrigued by the unfamiliar sensation of nerves only vaguely attached. "I am afraid," he said as smoothly as he could, as though a wretched sort of disbelief wasn't tickling the back of his throat, "that I am not Fullmetal."

There was a long, heavy moment of silence, and then Alphonse carefully asked, "If I may ask, then, who are you?"

Roy looked up at him and met light brown eyes that didn't look like they disbelieved him, which was...unexpected, honestly. "Brigadier General Roy Mustang."

Alphonse's eyes went wide, and then he covered his face with one hand. "If you're here..."

"Then Fullmetal is likely in Amestris," Roy finished when Alphonse didn't, his stomach doing an uncomfortable little flop at the thought. "The lieutenant is going to kill him. Me."

"Well, fuck," Alphonse decided, sounding _so much_ like his brother.

Roy couldn't help it, he just started laughing.

Only him and Edward could have something like this happen when they were in _different worlds_.

-0-

Ed's _extremely mature_ way of dealing with his situation, was to curl up on the couch, take a swig of Mustang's brandy – not bad shit – and go back through _everything_ that had happened the day before, trying to figure out if he'd done anything to set this mess into motion. (He could practically _hear_ Mustang's bland, 'What have you done _this_ time, Fullmetal?' He'd considered saying it out loud, for sheer familiarity's sake, but Mustang's voice sounded a bit off, and he didn't really need to make real what was already in his head.)

He still hadn't thought of anything he might have done – it had been a pretty normal day of riding trains until evening, then asking around whatever town they'd reached in hopes of finding even a _hint_ of that fucking _bomb_ – when there came a knock on the front door of the flat.

Ed twisted on the couch and peered over the back of the couch at the door, uncertain what to do. He hadn't bothered trying to find any clothing, so he was just in briefs and worn white shirt, which was far less clothing than he would be willing to open the door in in his _own_ body. And Mustang probably wouldn't care, given all the whoring he'd been known for when Ed was a kid – though the lack of mirrors was a rather disconcerting suggestion that that might have changed – but Ed was the one inhabiting the bastard's body, for the moment, and _damned_ if he was going to go around showing off everything Roy had to the neighbourhood. (As nice as that everything might be.)

"Fuck off," Edward muttered to his brain, because this was _not the time_. (Actually, it would _never_ be the time, because, current status aside, there was way too much distance separating Ed from the bastard for him to keep fucking _pining_ – Al's words, not his – for someone who'd only ever _tolerated_ him – _those_ were Ed's words, though Al had always looked uncertain when he'd said as much.)

(Ed was trying _very_ hard not to think about the photo of him in the bedroom. With the unused bed. Next to that photo of Mustang with his best fucking friend.)

There was silence from the direction of the door for a moment, then Havoc called, "Chief? The lieutenant's gonna shoot both our balls off if we're late."

Well, shit. Now what? Just because Mustang always _acted_ like he didn't give a fuck – or, he had when Ed was a kid; fuck knew how he was now Bradley was dead – didn't mean that Ed could actually manage to play the part until whatever shit this was wore off.

"I'm sick! Contagious!" he shouted back, hoped the weirdness of Mustang's voice would convince Havoc of that.

Havoc didn't say anything for a long moment, then there came the sound of a key in the lock and Ed moaned, sinking back down into the couch; of _course_ Mustang would have given Havoc a key. Just his luck.

Havoc was quiet as he stepped into the flat. But, once he'd closed the door, he said, voice tired, "That was more pathetic than usual. How much did you drink last night?"

Was this normal? Mustang falling asleep on the couch with a bottle of brandy in reach?

The naked bed suggested it was, and Ed's chest ached.

He swallowed and peered back over the back of the couch.

Havoc was standing in front of the door, eyebrows raised and his expression utterly unimpressed. "Sir, seriously."

"I'm not...the bastard. Mustang," Ed tried.

Havoc closed his eyes. "Please don't do this to me, sir. Not today."

"I'm not doing fuckin' _anything_ to you, dipshit!" Ed snapped, losing his temper a bit, and Havoc's eyes flew open wide, clearly shocked. "I'm the one stuck in the bastard's fuckin' old-as-shit body! And what's with the fuckin' 'not today' bullshit, anyway? What've you got, date number eight thousand?"

"B-Boss?" Havoc said, his voice gone weirdly high-pitched.

"Who else does this shit always happen to?" Ed shot back.

And then he realised what he'd just done and dropped his head to the back of the couch. " _Fuck_. Sorry, Havoc. Not angry at you." Well... "Mostly."

"I need to sit," Havoc announced and walked over to sit in the chair catty-corner to the couch Ed was huddled on. He cleared his throat as Ed turned to him, then asked, "So...what did you do?"

Ed shot him a flat look. "Why the fuck're you assuming it was _me_? Why can't it have been the bastard getting' into something he shouldn't've when he was out with whatever women of the night?"

Havoc blinked a couple times, and Ed couldn't tell if the thrown look was because of the whole situation, or what he'd just said. "The chief hasn't gone on a date, so far as I know, since–" He shrugged and looked away, clearly uncomfortable. "Well, since everything went down."

Ed frowned and touched the scarred space where Mustang's left eye used to be, remembering the missing mirror. Was the bastard...ashamed of his appearance? That wasn't at all like the Mustang Ed remembered.

Havoc cleared his throat. "So, if you're...here. That means the chief is–"

"In Rennes, with Al," Ed supplied, then groaned and dropped his face – _Mustang's_ face, really – into his hands as he realised the complications that would result in the other world from this switch. " _Fuck_. We're gonna lose that fuckin' bomb again if we miss the fuckin' train." He _really_ didn't want to spend another three months wasting their limited funds, travelling aimlessly around western Europe and trying to find any hint of the goons who'd reportedly stolen the plans for the damn thing.

Because he and Al'd managed to dismantle and safely destroy the original one that had gone through the Gate, but not before the Thule Society's scientists had examined it and created a blueprint that was, if not complete, close enough that it wouldn't be too hard for someone smart to fill in the gaps. And, of course, in the confusion following that mess, a bunch of arseholes had run off with the plans and started looking for a buyer. Because that was just how Ed's life went.

"I...don't think I want to know," Havoc said tiredly, and Ed looked up to find him pinching the bridge of his nose. He sighed, then looked back up at Ed. "Look, I can't begin to guess how to handle whatever this is–"

Ed very kindly didn't point out that, honestly, _neither did he_.

"–but it's probably best you just...stay here. Today."

"Ya _think_?" Ed snarked back.

Havoc managed a tired smile. "Sometimes."

Ed rolled his eyes.

Eye. Whatever.

"That doesn't work quite so well on the chief's face, boss."

"Get the fuck out, arsehole," Ed snapped back.

"I'll let Hawkeye know what's going on, so don't be surprised if she comes by around lunchtime to 'bring you papers to sign' or whatever."

"Yeah, okay," Ed muttered, not really looking forward to that, but aware that it would happen; no way he was going to get through this without the whole team popping by at one point. Which, if he was being honest, it would be nice to see them all again. One last hurrah, so maybe that little whisper of hope would finally die and he could resign himself to living in the other world, like he'd promised Al he would.

"Maybe best to put trousers on before then," Havoc added, and Ed shot him a scowl, only to be met with a scrap of black fabric being held out to him. "And this; I've never actually seen the chief without it. Bit disconcerting."

Ed frowned and took the fabric. Ties slipped down to hang on either side of his fingers, and Ed found himself looking at an eyepatch. He swallowed, couldn't help remembering, again, the lack of mirrors. "Yeah," he agreed quietly.

A hand landed on his shoulder, and Ed looked up at Havoc, found him forcing a smile under sad eyes. "And, Ed, if you switch back before I come by again, it was good. Talking to you again. Not the same without you around."

Ed had to swallow a couple of times, his – _Mustang's_ – throat gone tight. "Same," he offered and _fuck_ but that hurt to say. Getting Al back had helped make that other world bearable, but he would always miss the people he'd grown up with.

Fuck. Should he call Granny or Winry? It'd be weird, them getting a call from Mustang, probably. But...it would be good to hear their voices again, to tell them that him and Al were okay. Not settled – too much to do – but okay. Alive. Happy and sticking together. And, _yes_ , Ed was taking care of his automail; it was the only stuff he had.

Havoc squeezed his shoulder once, then stepped back and saluted him, holding it until Ed offered a rather sloppy one back, then left Mustang's flat.

Ed looked back down at the eyepatch again, feeling tired and lonely in a way he hadn't suffered since Al had come back to the other world with him.

"I want to go home," Ed whispered in his stranger's voice, before closing his eyes and letting out a helpless laugh.

He didn't have a home.

-0-

Despite the mind-swap, Alphonse had insisted that they couldn't miss their train, which meant Roy had to rush through getting ready in an unfamiliar body. And...

While, having both eyes was a noted improvement in terms of his spatial awareness, the weight of the automail was far more than he ever could have guessed, especially having seen the way Edward would dance around a battlefield like his body weighed only a little more than a feather. His respect for his former subordinate climbed another notch, and he hated, a bit, that he would never be able to _tell_ Edward how much more he appreciated his skills now he was experiencing the pains of automail for himself.

"Why is catching this train so important?" Roy gasped to Alphonse as they ran down unfamiliar streets. The architecture wasn't _that_ different from parts of Amestris, which was reassuring, and the language sounded familiar in that way that a language that shared its roots with one you knew often did.

(And, once again, the fact that he was even _able_ to speak while running was impressive, especially with the added weight of metal limbs; Edward hadn't slacked in keeping his body in shape, had he? Not that Roy had ever expected anything less from him.)

"We're trying to find a group of thieves," Alphonse replied, apparently also plenty enough in shape to run and talk. "We've been following them since we got word about them nearly two weeks ago."

"What did they steal? Why not leave it for the law to handle?"

Alphonse just shook his head, and Roy hoped that was just caution speaking, and not a case of Edward's usual refusal to ask for help.

They did manage to catch the train, somehow, and Alphonse, at least, seemed to speak the local language, which was good.

"I don't suppose," Alphonse said as they walked through the train cars, looking for a seat, "you happen to speak any languages other than Amestrisan? Brother's the one who's fluent in French and German."

Roy was going to pretend those meant something to him, even though they didn't. "I learnt Cretan as a child, but I haven't practised it in years."

Alphonse scratched at his nose and motioned for Roy to take a seat in the facing benches he'd found first. "I think Brother said that correlates to Spanish, here? We're going the wrong way, at any rate."

Roy shook his head. "And where are we?"

Alphonse blinked a him a couple times, then let out a tired laugh as he dropped into his seat. "I suddenly know exactly how Brother must have felt when I first joined him here," he said, and Roy couldn't quite help a grimace. "It's fine, sir, I don't mind. It's just...weird."

Alphonse took a deep breath and sat back against the train bench. "Uhm, we're in the French Republic, which is a country on the same landmass as Germany, where Brother was living when everything happened two years ago. Which, I know, that...probably doesn't help any."

"Not particularly," Roy admitted.

Alphonse grimaced. "Sorry. Brother had a map, and it still took me a couple months to sort it all out." He sighed. "Basically, Germany is behind us, to the east, while we're headed west, toward the ocean."

Roy raised his eyebrows at that; he'd never seen the ocean before.

"We just left the city of Rennes, and we're headed for Brest, which I guess is on the ocean? Brother made some complaints about how sea travel didn't agree with him when we found out that's where they were headed."

Well, that boded well, with Roy stuck in Edward's body.

"I see. So, essentially, just come along quietly and hope Fullmetal figures out how to fix this," Roy assumed.

Alphonse frowned. "If he can," he cautioned. "I mean, he'll have better luck in our– back, uhm, back there, since there's no alchemy, here–"

"You're joking," Roy said flatly, even as something a little like panic took flight in his chest; no alchemy? Given, he hadn't made use of his flame alchemy in a while, but at least he still _had_ it.

Alphonse's eyes were grim and tired. "I'm not," he said quietly.

Roy squeezed his eyes shut and ached for Edward, trapped in this world for four years and completely cut off from the alchemy he'd practically lived and breathed throughout his youth.

He wouldn't blame Edward if he didn't make returning a priority.

-0-

Ed had been going back and forth between the short stack of alchemy books he'd found buried in the back of Mustang's cupboard and the phone for almost two hours, when Hawkeye let herself in. "Hi, Lieutenant," he offered from where he'd been standing next to the phone, staring at it. "Good to see you again."

She blinked once, then said, "Edward," in greeting, before stepping past him and setting a pile of papers down on the living room table, next to the bottle of brandy Ed had been somewhat constantly reminding himself wasn't an option, no matter how much more courageous it might make him feel. "I would say it's similarly good to see you, however..."

"Yeah, sorry. You're kinda stuck staring at Colonel Bastard's ugly face."

Her mouth twitched at that. "Rather." She motioned a hand toward the couch while taking the chair Havoc had used earlier. "Please, sit. I can walk you through the brigadier general's day yesterday, see if we can't find some correlation that could have caused this."

Ed made a note of the promotion – the last time he'd seen Mustang, he'd been wearing a corporal's stripes, and Al had explained about the self-demotion and what he knew about Mustang's brief promotion to brigadier general by Bradley to get him out of Central; good to know he'd got that back at least – even as he nodded in understanding. "It's unlikely to have been something I did in the other world, but it would help to know what Mustang got up to yesterday."

Hawkeye frowned at him. "Don't be so quick to assume, Edward. You, more than anyone, should know how easy it is to set off an array on accident."

"I do," Ed agreed, unbothered by her chastisement mostly because she clearly didn't understand. "But alchemy doesn't work in the other world; there is _literally_ no way this was my fault."

Her eyes had gone wide at the mention of no alchemy. "Then, the general is defenceless?" she whispered.

Ed bit his – Mustang's – lower lip and had to look away. "Al's there with him. And it's not like my _body's_ defenceless; as long as Mustang thinks to use the right side, the automail packs more than enough of a punch even _without_ trying."

Hawkeye let out a careful breath. "We'll have to trust that they'll stay out of trouble, then," she decided.

Ed couldn't bring himself to look at her; he and Al _desperately_ needed to catch those fuckers, which meant no way they'd be out of danger. But – and he believed Mustang would agree with him here – even if it meant his or Al's life, better that than the hundreds of thousands those plans could kill. And, with luck, the death of Ed's body would just switch them back, or something, and Ed would be the one to kick the bucket, while Mustang got back to life here. Far from an ideal outcome, but at least there were fewer people who would miss Ed.

That was disheartening, but true.

Hawkeye cleared her throat, then began reciting Mustang's day. Which sounded...expectedly boring. The only time she couldn't account for was the time after Mustang had gone home that night, which Ed suspected _he_ could account for just fine on his own, between waking on the couch and the brandy bottle still staring at him. Not to mention the complete lack of alchemy materials that hadn't been shoved away, as though their owner had settled into the old 'out of sight, out of mind' adage.

"So," Ed said at last, "if it wasn't something _I_ did, and it wasn't something _Mustang_ did..."

"That means this was done by someone else," Hawkeye finished for him, the concern in her eyes something Ed was totally on board with, "and likely with the intent to do one or both of you harm."

And, if they were going to catch the culprit, they were going to have to draw them out into the open. Ed tried not to sigh as he said, "I'm going to have to come in and play Mustang, aren't I?"

"I'm afraid so, sir."

Ed grimaced and stood. "And here I thought I'd finally _escaped_ that fucking uniform," he complained.

Her cough sounded like it might well have been attempting to muffle a laugh, and Ed counted that as a victory, if only to make himself feel a little better about this.

-0-

For the first time in a long time, Roy found himself _missing_ paperwork.

Ever since they'd got in to Brest, they'd been running around the city on their feet, Alphonse asking questions as best he could with his limited 'French', and occasionally defaulting to Amestrisan – 'English', apparently – when they came across someone who spoke it. Which, well, they at least seemed to be making _some_ progress, judging by the way Alphonse's tone got a little cheerier with each conversation.

Meanwhile, Roy _still_ had no idea what these thieves had stolen, and why it was so important for Edward and Alphonse to hunt them down on their own.

Well, at least the ocean – which they seemed to be moving closer toward with each helpful response – was stunning and helped balance the feeling of uselessness, a bit.

At last, they ended up on the docks, where a handful of _massive_ boats were sitting in a line over the water. Roy was reassured by discovering that he wasn't the only one staring, but Alphonse still snapped out of it faster, grabbing Roy's arm and calling, "Come _on_ , Brother!"

Clearly, being in this other world for so long meant the newness of improbable sights had worn off a bit.

The boat Alphonse led them up to looked like it was ready to leave, and the youngest Elric did some impressively fast talking to get them onto it before it did.

"This," Roy commented as they watched the docks recede behind them, "should be fun."

Alphonse let out a slightly shaky laugh. "Right? Brother's going to _kill_ me when he finds out we're bound for America."

Roy frowned at that. "Is that a...problem?"

Alphonse shrugged. "It was one of the places Brother crossed off right off when we were trying to decide where we might like to settle down, after this is sorted."

Roy grabbed Alphonse's arm before he could start walking away. "Alphonse," he said in his best commander voice, which sounded oddly effective in Edward's slightly-off voice, "you need to explain what's going on. Specifically. _Now_."

Alphonse shot him a nervous look, then drooped a bit and nodded. "Yeah, okay. Let's find the cabin we got assigned, then talk in there."

Roy nodded agreeably and motioned for Alphonse to lead the way, since he was the one with the tickets.

As fate would have it, they never made it to the cabin.

In the lower levels of the boat, Roy heard someone shout something ahead of them, which included the name 'Elric', and then Alphonse was grabbing his arm and dragging him back around the corner they'd just turned, right before a shot rang out.

"Found them," Alphonse gasped, his eyes wide and vaguely panicked as he met Roy's stare. "Sir, I'm _so_ sorry. They have the plans to a bomb passed over from our world and Brother and I have been trying to get it to destroy it and this is just really horrible luck."

Plans to a bomb from _their_ world? No wonder Edward and Alphonse had decided to do things themselves.

"I think I understand what's going on," Roy promised, partway through reaching for his gloves before he remembered he didn't have them. And, even if he did, he couldn't use alchemy. "I don't suppose Fullmetal ever got over his aversion to guns?"

Alphonse laughed as he shrugged out of his jacket and sat it neatly over his suitcase on the floor. "Afraid not, sir," he offered, before ducking low and promptly slingshotting himself around the corner.

The shooting started again, bullets pinging off the wall across from Roy, and he took a deep breath – he was no hand-to-hand fighter, but he couldn't let Alphonse handle things on his _own_ ; Edward would never forgive him, even if Roy could manage to forgive himself – then followed Alphonse's example of keeping low as he swung around the corner.

A bullet immediately clipped the shoulder of the automail, and Roy ducked a little lower, hoped he didn't regret this, and tackled the first person he reached. It didn't take much effort to wrestle the gun from him – the automail was certainly good for overpowering people – and he used one bullet to shoot that man in the head, then the next two closest, taking them both out.

Having two good eyes was doing _wonders_ for his accuracy.

He heard Alphonse's voice around another corner, speaking an unfamiliar language. He didn't sound particularly panicked, so Roy took a minute to check how many bullets he had in his stolen gun – at least _these_ were the same – and quickly scrounged up enough for a full magazine, between the three men he'd killed.

Once the full magazine had clicked back into place, Roy moved toward Alphonse's position, and found him crouched behind a pallet of something in tough bags, shouting at someone out of view. He frowned when he spotted the gun in Roy's hand as he joined him, but shook that off at another taunt from the other side of the pallet.

Roy mimed a question.

Alphonse grimaced and, while the other person was talking, quietly explained, "They say they've completed another bomb, but Brother was certain they haven't been near any labs capable of producing uranium, which means they're either bluffing, or we missed something."

"So it's a stand-off."

Alphonse sighed and nodded, then called something back.

Roy twitched as he heard what sounded suspiciously like heavy, military boots thudding against metal. "We have company coming. Military."

"Navy, more likely," Alphonse corrected, even as he lifted his crouch enough to move. "We can't let that bomb – completed or otherwise – fall into anyone's hands; this world is a powder keg on the eve of another war, and the person with the most devastating weapon–"

"Wins," Roy finished grimly, getting up enough to move, himself. "Let me go first; you're not trained for this."

Alphonse's eyes caught on the gun in his hand again and he winced, but nodded, motioning for Roy to go ahead, then calling something back to the person talking to them again.

Roy peeked carefully around their barrier and, upon finding an empty hallway, crept out from behind their cover, gun cocked to shoot anything that moved. The other side of the pallet was empty, too, but a door a little ways down the hall was open, and the voice seemed to be coming from there.

Moving a bit quicker, now, Roy made his way to the wall just outside the doorway, waited until Alphonse had joined him, then peeked quickly around the doorway.

There was a man standing in the middle of the room, holding something that looked vaguely bomb-like, and pointing a gun directly at Roy's head.

He ducked back around right before the man shot, and the bullet clanged harmlessly against the far wall.

On the other side of the pallet they'd just crept around, someone called something in 'French'.

"Sir?" Alphonse whispered uncertainly.

Roy shook his head. "He's holding it. If I shoot him and it's finished, it could go off when he drops it."

Alphonse closed his eyes for a moment, swallowed, then turned to Roy with that same self-sacrificing, determined look Roy had seen on Edward's face right before he'd vanished from their world both times. "We don't have a choice," he whispered.

Roy nodded, took a calming breath, then twisted himself around the doorway, firing before he even knew he had a clear shot.

His aim was true, though, the bullet knocking the other man's head back with the force, but the man also connected, and Roy hissed as he pressed a hand against the side of his neck. A nick, it felt like, but _still_. That had been a little too close for his comfort. _Especially_ when he remembered that this wasn't his body.

Alphonse, in his infinite wisdom, had darted around Roy as he was shooting and run forward to catch the potential bomb before it could hit the floor. "Are you okay, sir?" he called at Roy's hiss.

"Minor cut," Roy promised, stepping forward to look over the object in Alphonse's hands. "Is this–?"

"It looks like it," Alphonse agreed, his expression tight as he carefully looked it over. Then he frowned and turned the bomb so Roy could see what looked like an array carved into the casing. "Alchemy?"

"I thought you said it doesn't work here?" Roy asked, reaching out to touch the edges of the array.

"It _doesn't_ ," Alphonse insisted, right before Roy's blood-covered fingers brushed the array, and it lit up with bright, sickly green light.

"Alphonse!" Roy shouted, grabbing the boy to– He didn't know what. Pull him away from the bomb in his hands?!

Everything went white.

-0-

Playing Mustang all day had got them less than nothing, and Ed completely understood the urge to drown himself with alcohol on the couch; it wouldn't help with their current problem, but at least it would dull the tension headache born from... Actually, Ed wasn't certain whether to blame the harsh lighting of Command, the general stress of the situation, or trying to compensate for only having one eye to see through.

 _Fuck_ , how did Mustang do this every day?

He was just crossing the parade grounds with Havoc and Hawkeye – he'd been accompanied by at least two members of the team all day, for which he was oddly grateful, their familiar presence reassuring – when a bright light lit up just ahead of them. Hawkeye and Havoc both stepped forward with guns out, pushing him back, while Ed fell easily into a fighting stance.

As the light started to dim, though, Ed recognised a familiar shade of hair, and pushed past Hawkeye and Havoc, shouting, "Al!"

And, indeed, it was his brother and his own body – which was vaguely disconcerting – laying in a heap in the middle of the parade grounds.

Ed knelt next to his brother and pressed his fingers against his throat, relieved to find a pulse; by all appearances, Al was just knocked out.

"Edward," Hawkeye called quietly, and he looked up to find her next to his own body, a wound on the side of his neck bleeding sluggishly.

He swallowed, dizzy for a moment, and shook his head. "Is he alive?" he asked.

"So it seems," she agreed, pressing her hand against the wound with the sort of military efficiency that Ed really wished he had right that moment. "We should get them to hospital."

She was right, and he nodded before rising with Al's body. (And, _fuck_ , when had his brother got so heavy? Or was Mustang just _that_ weak? Ed was going to give the bastard hell for this, right after he figured out what had happened.)

As Havoc picked Ed's body up, a gun clattered to the walkway, and Ed's eyes widened in disbelief, before he snorted and shook his head at himself; Mustang was a distance fighter, and he had nothing against using guns, unlike Ed himself. If he was faced with people shooting at him, of _course_ he'd take one of their guns to use.

As disconcerting a thought as that was, Ed was suddenly a lot more grateful for the mind-switch, because Mustang had clearly done his damnedest to keep Al safe, and Ed wasn't certain he'd have managed half so well, himself; it was always a bit iffy when bullets started flying.

The trip to the hospital was relatively quick, and no one questioned the admission of the two Elrics, though Ed couldn't say if that was Mustang's authority – which you'd better fucking _believe_ Ed would throw around for his brother and the idiot in his own body – or just that, even in their dull clothing from Earth, Ed and Al were recognisable, and it sounded like – from a conversation he overheard between a couple nurses while they were patching the wound in his body's neck – the years hadn't lessened the notoriety of the Fullmetal Alchemist a bit.

At last, the medical staff cleared out, leaving behind Ed, his body, Al, and Hawkeye. (The latter had sent Havoc off somewhere, and Ed could only assume it was either damage control, or to inform the rest of the team before they heard whatever insane rumours Command started churning out.)

Ed frowned a bit as he stared at his own body. It was a bit queer, getting the chance to look at his own body as an outside observer, but also kind of interesting, in the same way a horrible accident is impossible to look away from.

He looked...tired, was the first thing Ed had really noticed. Like he'd been doing a lot more running than resting, which was true. And he was fairly certain the lines creasing the corners of his mouth and eyes – mostly smoothed away by unconsciousness – were worry or pain lines, not the laugh lines that he knew Al was well on his way to developing. Which, well, Ed was okay with that. He was fine with having noticeable stress lines at twenty, if it meant his brother had the chance to laugh more often. He was kind of disgusted that they were so obvious – no way Al hadn't spotted them, which meant he'd probably been privately worrying about Ed, _dammit_ – but it was a little too late to do anything about it.

He sighed and reached up to rub at his eyes, only remembering about the eyepatch when his fingertips touched it. Because he'd gone expecting the damn thing to be constantly in his way or uncomfortable or whatever, but either Mustang had found a really good one, or he'd just worn it so much, his body had adapted to it, even if Ed's own conscious hadn't.

"Well," a voice that _almost_ sounded like Ed's own said, "this is only a little disconcerting."

Ed looked up and met his own eyes, while Hawkeye shifted by the door. "Welcome to the world of the living, Brigadier General Bastard," Ed said, deadpan.

Ed's face twisted with smile that had an edge of fondness to it. "Fullmetal." He shifted in the bed and winced, reaching over with his left hand to rub at the point where flesh turned into metal. "Where are we?" Mustang asked, instead of enquiring after the aches and pains of Ed's body, which he appreciated; it was a lot harder to pretend they weren't a big deal when someone else was suffering them.

He shrugged and glanced toward the door and Hawkeye. "Central's military hospital. You and Al appeared on the parade grounds in a flash of light." He looked back at himself, waiting until Mustang had traded nods of greeting with Hawkeye, looked toward Al – his shoulders relaxing a bit at seeing him, like he'd been afraid something might have happened to him – and turned back to him, before narrowing his one eye and demanding, "What the _fuck_ happened?"

"Your tendency toward dropping explicatives is ruining the effect a bit," Mustang offered with a smirk.

"Mustang, so help me, you do _not_ want me to prove I know exactly where to punch myself so it hurts like a fucking son of a bitch."

Mustang swallowed. "Ah." He scratched his – Ed's – nose as he shifted on the bed to sit up, wincing a bit as he did so. "You were after a group that had stolen bomb plans from our world? Here."

Ed nodded. "That mission you sent me to when I was, uh, fuck. Fifteen? The guy in the self-made mining island on the lake."

"The one you blew up?" Mustang asked drily.

Ed flashed him a smile. "That one!"

Mustang's trademark 'I can't believe I have to put up with your shit today, Fullmetal' look looked _really_ weird on Ed's own face, but it actually sort of worked, a bit, too, and Ed was going to have to remember that next time he needed to give someone an unimpressed stare.

Ed waved a hand at him. "Shut up. Anyway, I told you the moron'd built a bomb, and that it vanished when he tried human transmutation, right? Turns out it ended up on Earth, and the Thule Society – the ones behind the invasion two years ago – they'd got their hands on it. Al and I managed to destroy that original one, but in the mess from the Thule Society's collapse, a group of thieves decided to grab the plans and try to find a buyer."

Ed's face twisted with a grimace and Mustang agreed, "Alphonse said something about that world being on the brink of war."

Ed's smile was not a happy one; he was glad his brother would never have to suffer the terror of an air raid, now they were back in Amestris. "Yes," he agreed. "We didn't realise they'd run off with it right away, had started to settle down a bit, then heard rumours through some of Hohenheim's contacts who I've kept up with. We should have been right on their tale."

"You were," Mustang agreed, watching Ed like he could read into his very soul. "They had boarded a big boat to somewhere Alphonse called 'America'?"

"Ship," Ed corrected, before it occurred to him what Mustang had just said, and he winced at the idea of having to survive the long sea voyage to America. Or, better yet, having to wake up there, given all the mocking comments he'd heard about them from the British and German people he'd become acquainted with during his time there.

"We found them in one of the lower levels," Mustang continued, as if Ed hadn't corrected him, "and they started shooting when they recognised us. Well, you and Alphonse." Mustang raised Ed's eyebrows at him, as if to say 'must you stir up opposition _everywhere_ , Fullmetal?'

Ed curled Mustang's lip in a snarl in response. "And you took one of their guns," he assumed.

Mustang blinked, then shrugged. "Yes. Not all of us are hard-wired to punch first, Fullmetal."

Ed made it as obvious as possible that he was rolling Mustang's eye at him.

Mustang coughed, then continued, "One of them had what appeared to be a working prototype and a gun. There were soldiers approaching, so we were rather rushed, and I'm afraid I took a hit to take him out." He touched a hand to the bandaging over the wound on Ed's neck.

Ed shrugged. "I've suffered worse," he returned carelessly.

The look Mustang levelled on him as he moved his hand to touch the automail shoulder was somehow both unimpressed and heartbreakingly sad, and Ed had to look away.

Mustang cleared his – Ed's – throat, then said, "There was what looked like an array on the side of the bomb casing, but Alphonse suggested alchemy doesn't work there?"

"It doesn't," Ed agreed carefully, because the way Mustang had said that...

"Yet, when I touched the array, it set the bomb off," Mustang said, his – _Ed's_ – eyes sharp with a question: 'You know what happened, don't you, Fullmetal?'

Ed swallowed because, yeah, he had a hypothesis, because he'd managed to activate an array on Earth before, and been there when Envy and Hohenheim had activated it again. "There was blood on your hand," he said, because he'd watched the nurses clean it off.

"Yes," Mustang agreed.

"My blood."

Mustang frowned, something that might have been regret darkening Ed's face. "Yes," he said, tone gone brisk.

Ed shrugged. "Al could probably have done it too, honestly," he offered, a bit carelessly. "Something about the blood of someone who's jumped worlds has the ability to activate arrays; I did it once on accident, and the one two years ago was activated with Hohenheim's blood." Then he frowned as another thought occurred to him, and he looked back at Mustang, only sort of noticing his troubled expression. "You said you were on a ship bound for America?"

"Yes," Al said, and Ed jerked his – Mustang's – head up to look at his brother, feeling a shit-tonne of tension leave him to see him awake.

"Hey, Al."

Al smiled at him, though it looked a little troubled. "Brother. What were you saying?"

"Ocean liner?" Ed asked for clarification.

Al blinked a few times, then shrugged. "I guess? You know more about ships than I do."

Ed made a face, because he _always_ got seasick on boats, even just crossing rivers, and Al let out a slightly startled giggle and hid his face behind one hand.

" _Fullmetal_ ," Mustang stressed.

Ed shook his head and looked back at his body, which was wearing Mustang's patented 'Any day, now, Fullmetal' stare. He sighed, then said, "Travel between the worlds takes a lot of energy. If the bomb exploded on an ocean liner, even if it was only a quarter full, that would probably have generated enough energy to shoot you both back to this world without you getting caught up in the blast. Although..." He frowned, because that trick shouldn't have worked for him, not since he'd died on this side of the Gate twice. Travelling _through_ the Gate via ship was one thing, but being sent back through to save his life, body and soul–

 _No_. Not _his_ soul, but _Mustang's_. His soul was already in Amestris, inhabiting Mustang's body. Mustang hadn't been able to just return his consciousness, because there was no where to go, so Ed's body had come with; an explosion that size would have generated more than enough energy.

But, what if they _hadn't_ swapped? Would he have died in that explosion, while Al was sent back to Amestris alone?

Something twisted unpleasantly in his stomach at the thought of his brother being forced to keep on alone, without any chance that Ed could still be able somewhere.

"Edward?" Mustang said, right before Ed's flesh hand touched one of Mustang's.

The world flipped and twisted and turned all over, and Ed had one moment where he thought he was floating, and then he slammed back down into the familiar aches of his body with a gasp.

Al and Hawkeye were both making panicked noises, but Mustang interrupted them with a firm, "We are both _fine_. Fullmetal?"

Ed raised his head and found himself looking into a single dark eye, which looked maybe a little concerned? "Yeah," he said, forcing himself to straighten and ignore the familiar tug of his automail. "I'm fuckin' _fantastic_. Warn a guy 'fore you go around being all touchy-feely with his hands. Bastard."

"Technically," Mustang pointed out with a superior air, both of them ignoring the quiet breaths of relief Al and Hawkeye weren't particularly quiet about, "I was being 'touchy-feely' with my own hand."

" _Technically_ ," Ed shot back, "you were using _my_ hand to do it. And get that fuckin' stick out your arse, ya' bastard. It's fuckin' _uncomfortable_."

Someone let out a choked noise from the doorway while Al just moaned, and Ed twisted to find Havoc and Breda crowding their way into the room, shortly followed by Fuery and Falman. Havoc was doing his damnedest not to burst out laughing, judging by the hand clapped over his mouth, while Breda looked like he was having the time of his life, and Fuery was bright red and failing at not smiling, while Falman was somehow managing to look completely unflappable, just like Hawkeye.

"Boss," Breda said with a wide grin, "we seriously missed you."

"Mutiny," Mustang muttered, even as Havoc gave up and started cackling, holding out a hand to get a high-five from first Breda, then Ed, who politely _didn't_ smack his hand hard enough to make it go numb.

They didn't get to visit long, as a nurse came in to shoo them out for being too loud, but it was good to see them all again while Ed was _himself_. And, too, the last time they'd seen Al, he hadn't remembered his time in the armour, so it was a special treat, watching them realise he actually _knew_ them.

Hawkeye ended up leaving with the others, making some comment on Mustang being able to walk himself home. She'd also ascertained from the rest of the team that, yes, Ed and Al were back in the books as living, so they shouldn't have any trouble getting a place to stay once they were released in the morning, assuming they could get access to whatever money Al'd had left from his travels.

Al said something about calling Winry, then followed Hawkeye from the room, leaving Ed with Mustang.

They were both quiet for a long minute, Ed unable to bring himself to even _look_ at Mustang. Because, joking aside, what _could_ he say?

"Does it always ache like that?" Mustang asked at last.

Ed turned to frown at him, found the bastard watching him with his single, tired eye. He almost lied, insisted it was the salt air, or the damp climate, or the heat or the cold; everything he'd ever told someone who had caught him wincing and rubbing at one of his ports.

But he couldn't, not after walking a day in Mustang's shoes, suffering his lonely flat with no mirrors and a bottle where he'd fallen asleep. "More or less," he admitted, giving in to the ever-present need to kneed at the ache of his shoulder, gravity always making that one worse. "The weather can make it worse. Judging by when I went to sleep over there, it probably wasn't one of my good days, but it wasn't a _bad_ day, either."

Mustang offered him a lopsided sort of smile that Ed had never seen on him before. "I suppose I can understand why you're always so grumpy."

"Fuck you!" Ed snapped, and Mustang laughed, free and open and fucking _weird_.

Ed huffed a bit and left off his shoulder to point at the eyepatch. "As one person with ugly fuckin' scars to another; being ashamed isn't gonna help you a fuckin' bit."

Mustang stiffened. "I'm certain I have no idea–"

"Then where're your mirrors?" Ed demanded, not letting him finish. "Why do you wear it fuckin' _everywhere_?"

Mustang gave him a hard look. "I don't think that's any of your business, Fullmetal," he said in that stiff tone that meant Ed had gone too far.

But Ed wasn't a kid any more. He knew loneliness, and he knew depression, knew holding everyone at arm's length, because he hated himself for something that he couldn't have fixed.

He remembered a photo of himself next to a photo of Hughes and Mustang; the only signs of personalisation in a room that never got slept in.

"So," Ed said coldly, eyes narrowed, "you can ask about my automail, but I can't ask you about anything? Have you given up on the rules of equivalence? Is that why your alchemy books were shoved in the back of a cupboard?"

"You went looking through my _things_?" Mustang demanded, rage burning in his eye. It made him look so much more alive than he had done.

Ed flashed him a smile that was all teeth. "What else was I supposed to do? Drink all the brandy? _Tempting_ as that might have been, not all of us enjoy waking up with a hangover every morning."

"Don't you _dare_ speak of what you don't understand, you little brat," Mustang hissed, voice gone low and cold, like he thought that would scare Ed away when hot rage hadn't.

"You think I don't know how it feels to drink myself to sleep every night?" Ed hissed right back, leaning forward and staring at the single black eye. "You don't know a fucking _thing_ about my life over there, Mustang. _No one_ does. I'm not that scowling boy you've got a photo of on your dresser, any more; your shitty short jokes aren't going to derail me."

That deflated Mustang, and he looked away, his shoulders slumping. "I wear the patch because I don't like the looks I get if I don't," he muttered.

Ed looked down at his automail arm, laid bare without the long-sleeved shirts he'd worn since he'd got it, hating the pitying way people looked at the shining steel. He still hated that, but he'd finally got to the point where he didn't _need_ to hide it. At least, not around people who knew about the prosthetic, like Noah and the Als and Gracia. And so many others he'd finally let himself befriend in Germany.

He looked up and, finding Mustang still wasn't looking at him, his blind side turned toward Ed, he reached up and grabbed the eyepatch off.

" _Fullmetal_!" Mustang roared, turning to glare at him, even as he lifted a hand to hide the scarred mess where his eye should have been.

Ed caught his wrist in his automail hand and quietly said, "I want to see."

Mustang's jaw was clenched tight, but he let Ed pull his hand down, out of the way.

Ed looked over the scars he'd only been able to feel, before, and he still felt regret, that Mustang had lost it, but he knew something of sacrifice and learning to live with what you'd given up while chasing your goals. So he didn't let himself feel any pity as he met Mustang's remaining eye and said, "Looks like someone's bullet missed your brain. Shame." And then he flashed his best little shit grin.

Mustang's eye widened, and then he reached forward and – instead of punching Ed, like he'd honestly probably have deserved – caught the back of his head and pulled him forward to kiss.

Ed allowed himself about half a second of shock, then caught a fist in the front of Mustang's stupid fucking uniform jacket and pulled him just that little bit closer, even as he melted into the kiss, just a bit.

When Mustang eventually pulled back, there was a hint of a flush on his cheeks – Ed was pretty damn sure he had one of his own, _shit_ – and he was smiling, just a bit. But it was honest, lacking the sharp-edge superiority Ed had grown up seeing. "Welcome home, Edward," he murmured.

Ed couldn't quite stop a smile, even as he rolled his eyes and muttered, "Whatever. Moron."

Mustang kissed him again, which suited him just fine.

.


End file.
